The present invention relates to a carburetor for combustion engines with a mixing chamber located in the carburetor housing. This chamber is bounded downstream by a randomly actuated mixture throttle and upstream by an air throttle which controls the intake air cross section and is actuated by the pressure prevailing in the mixture chamber. A bypass air duct discharges into the center of the mixing chamber and into which the fuel supply discharges. A nozzle pin cooperates with the air throttle and controls the cross section of a fuel jet.
Such a carburetor is disclosed in the German Laid-Open Document No. 25 16 949 as a rotation symmetrical carburetor in which air throttle and throttle flap are pipe-shaped. Even though this carburetor determines the fuel-air ratio, especially in the partial load range as a function of the air mass flow, the present invention has the object to provide an arrangement to comply with the increasing severity of pollution laws and to allow a regulation in a simple manner.
Another object of the present invention is to provide a carburetor of the foregoing character which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide a carburetor, as described, which may be easily maintained in service and which has a substantially long operating life.